Coloring matters of the phthalocyanine type



Patented May 28, 1 946 UNITED STATES PATENT OFFICE COLORING MATTERS OFTHE PHTHALO- CYANINE TYPE No Drawing.

10 Claims.

This application relates to the manufacture of coloring matters of thephthalocyanine series,

. and constitutes a continuation-in-part of our copending application,Serial No. 698,216, filed No- 5 vember 15, 1933 (2,116,602 issued May10, 1938).

It is an object of this invention to provide an improved process for themanufacture of coloring matters of the phthalocyanine series. Other andfurther important objects of this invention will appear as thedescription proceeds.

In British patent specification No. 322,169 there is described a processfor the production of blue to green coloring matters by heating phthalicanhydride. with ammonia and certain metals or 33 metal compoundsincluding iron, cuprous chloride and nickel sulphide. In British patentspecificatlon No. 389,842, (corresponding to U. S. Patent No. 2,000,051)there is described a process for the production of nitrogen-containingcoloring mat- 2 1) ters of complex constitution which comprises heatingan o-cyanoarylcarboxyamide in the presence of specified metals and metalcompounds.

These coloring matters are described as purple to green in color andstated to appear to belong to one general class, this class appearing toinclude the said coloring matters of British patent specification No.322,169. British patent specification No. 339,842 also describes theproduction of metal-free coloring matters and gives probable :11)formulae for a coloring matter containing magnesium and thecorresponding metal-free coloring matter.

British patent specification No. 390,149 (con responding to U. S. PatentNo. 2,000,052) deri scribes the production of the same coloring mattercontaining magnesium-and the corresponding metal-free coloring matterand of substituted'de rivatives of these by heating a phthalimide withammonia and magnesium or antimony.

As described in the last mentioned patent, the metal-free compound maybe produced either directly by heating a phthalimide with antimony, orindirectly, that is by first heating the phthalimide with magnesium toproduce a magnesium- 43 containing compound, and then eliminating themagnesium by precipitation from concentrated sulfuric acid. I

We have now found that coloring matters of the same general series maybe obtained by heat- 5 ing an o-arylene-dicyanide with a metal of thesecond group of the Periodic Table or a compound of such metal. Forinstance, when phthalonitrile is heated with zinc chloride at about theboiling point of the former and in the proportion of from 55 1 to 2moles of the latter for each 4 moles of the Application May 14, 1936,Serial In Great Britain November 16,

former, a greenish pigment is obtained containing combined zinc. It is,apparently, zinc phthalocyanine. When phthalonitrile and magnesium metalare heated under similar conditions, a magnesium-containingphthalocyanine is obtained of the probable empirical formula(CsI-hNzMMg. If the latter is dissolved in concentrated sulfuric acid,and reprecipitated'by dilution with ice, 2. metal-free phthalocyanine isobtained, which anpears to be identical with that obtainable in U. S.

Patent No. 2,000,051, Example 7.

In like manner, calcium, barium, or compounds thereof give upon heatingwith phthalonitrile a phthalocyanine containing the corresponding metal,from which, however, it readily parts upon precipitation fromconcentrated sulfuric acid.

The heating may! be effected immediately be tween theo-arylene-dicyanide and the metal or metal compound, or it may becarried out in the presence of a suitable solvent or diluent. Highboiling inert organic solvents, such as naphthalene or methylnaphthalene are particularly suitable for this purpose. such asquinoline, pyridine, or dimethylaniline may also be employed. Ifdesired, ammonia gas may be circulated through the reaction mass. Withthe alkaline earth metal, where the metallic form of, the reagent isemployed, it is preferable to carry. out the reaction in alcohol,especially amyl alcohol (normal or iso) or cyclohexanol.

The temperature of the reaction will depend on the boiling point of themixture employed, and

will generally be within the range of 150 to 400 C.

The reaction is applicable to substituted phthalonitriles, such ashalogen, methyl or nitrophthalonitriles, as well as to the -o-dinitrilesof naphthalene and anthracene. Thus pigments containing zinc can be madefrom zinc chloride and chloroor dichloro-phthalonitrile ornitrophthalonitrile or from other metals or metal compounds with similarnitriles. I

The so-obtained coloring matters are typically blue to green in shade,have only little or no solubility in organic solvents, but dissolve inconcentrated sulfuric acid and are decomposed by nitric acid. Theycontain nitrogen, are of complex constitution and contain the respectivemetal in combined form. However, except for the coloring mattercontaining zinc the metal readily splits off upon precipitation fromconcentrated sulfuric acid.

The magnesium-containing compound from phthalonitrile and magnesium isthe same as the magnesium-containing one described in Britishspecifications Nos. 389,842 and 390,149.

Tertiary bases,

Working according'to this new process the coloring matters are,generally speaking, formed with greater readiness than according tothose of the above-mentioned specifications and higher yields, in somecases nearly the theoretical, are obtained. Purification may be effectedas already described in the said specifications, i. e. byrecrystallisation, sublimation or washing with liquids which willdissolve impurities.

The coloring matters may be employed as pigments. For instance, they maybe made into lakes with the usual substrata; Such lakes may be used ascoloring matters for varnishes and inks.

The following examples in which parts are by Weight illustrate but donot limit the invention.

Example 1 5 parts of calcium turnings, 240 parts of amyl alcohol andparts of phthalonitrile are mixed and refluxed for 5 hours. The mixtureis allowed to cool, diluted with alcohol, the insoluble matter filtered01? and washed with cold dilute hydrochloric acid, hot water and alcoholand dried. The dry substance is green in color, insoluble in quinolineand other organic liquids and contains combined calcium.

The calcium-containing compound is converted to the metal-free one bydissolving it in concentrated sulphuric acid, pouring the solution intoWater, filtering off the precipitate, washing and drying. The drymetal-free compound is green ish-blue in color.

Example 2 12.8 parts of phthalonitrile are ground and intimately mixedwith 2.8 parts of calcium oxide and the mixture heated at 260 C. withstirring for 1 hour. The resulting solid or semi-solid is cooled,ground, and the ground material washed with boiling alcohol and thenwith cold dilute hydrochloric acid, and water and dried. The resultingcompound contains calcium and is the same as the corresponding compoundof Ex ample 1.

Example 3 15 parts of phthalonitrile are ground and intimately mixedwith 7.5 parts of baryta (BaO) and the mixture heated at 290 C. for 2hours. The resulting mass is allowed to cool, ground, extracted withboiling alcohol and dried. The dry substance consists of a coloringmatter containing combined barium contaminated with a little baryta. I

The barium-containing compound is converted to the metal-free one byheating with dilute hydrochloric acid, filtering, washing with dilutehydrochloric acid to remove any residual traces of barium compound,washing with water and drying. The dry substance is greenish-blue incolor.

Example 4 6.5 parts of phthalonitrile and 4 parts of anhydrous bariumchloride are heated with stirring at about 300 C. for-several hours. Theresulting mass is cooled, ground and extracted with boiling alcohol anddried.

Example 5 12.8 parts of phthalonitrile are mixed with 1.2 parts ofmagnesium powder (the magnesium powder having been shaken up with dilutehydrochloric acid, washed and dried immediately before use in order togive a clean metallic surface) are heated with stirring at about 270 C.for several hours. The resulting mass is allowed to cool, ground,extracted with boiling alcohol, and cold dilute hydrochloric acid, andwater and dried. The resulting compound contains magnesium and is thesame as the magnesium-containing compound described in British patentspecification No. 389,842.

Example 6 0.5 part of magnesium oxide is added to a. solution of 2 partsof phthalonitrile in 5.5 parts of quinoline and the mixture is heatedfor several hours at 220230 C., while a stream of ammonia is passedthrough. The resulting mass is cooled, diluted with acetone, the solidmatter filtered off, washed repeatedly with acetone, and then ex tractedwith warm dilute hydrochloricv acid, washed with water and dried. Theproduct contains magnesium. and is the same as that of Example 5.

Example 7 12.8 parts of phthalonitrile are mixed with 3.2 parts of zincdust and heated at 240 C. with stirring for 3 hours. The resulting massis cooled, ground, extracted with alcohol and dilute hydrochloric acidand Water and dried. The dry material is finally purified byrecrystallising from quinoline.

The recrystallised material is greenish-blue and analysis shows that itscomposition corresponds to (Cal-BN2) 4Zn. Sulphuric acid does not removezinc from this compound but forms a green addition compound with it.Other acids, for example hydrochloric and hydrobromic-also form additioncompounds. These addition compounds with sulphuric or other acids arereconverted to the initial compounds on treating with alkalies.

Example 8 12.8 parts of phthalonitrile and 3.4 parts of zinc chlorideare heated together with stirring at 230-240 C. for about half an hour.The resulting solid mass is cooled, ground, extracted with boilingalcohol, and dried. The dry substance is green and analysis shows thatits composition is On treatment with sodium hydroxide it yields a bluercompound of composition C32H15NeZnC1. This bluer compound on treatingwith hydrochloric acid reverts to the initial compound. The initialcompound appears to be zinc monochlorophthalocyaninehydrochloride,

(C6H4C2N2) 3(C6H3C1C2N2) ZNHCI,

and the second compound to be (C6H4C2N2) 3(C6H3C1C2N2) Zn.

On treating either of these compounds with concentrated sulphuric acid acompound which appears to be the corresponding sulphate is obtained.Similar com-pounds may be obtained with other acids.

Example 9 verted to the metal-free one by dissolving it in concentratedsulphuric acid, pouring the solution into water, filtering off theprecipitate, washing and drying. It is greenish-blue in colour.

Example 10 v 12 parts of phthalonitrile and 3 parts of cadmium oxide(CdO) are intimately mixed and heated together with stirring at about250 C. for 1 hour. The mixture is allowed to cool, extracted withboiling alcohol and dried. The dry substance is the cadmium-containingcompound described in Example 9.

Example 11 20 parts of phthalonitrile and 3 parts of beryllium powder(the beryllium powder having been shaken up with dilute hydrochloricacid, washed and dried, immediately before use in order to give a cleanmetallic surface) are mixed and the mixture gently boiled. After abouthalf an hour the mixture becomes semi-solid and after 1 hour the mixtureis allowed to cool, ground and the residual beryllium metal removed in asimilar way to that of Example 9. The resulting product is thenextracted with alcohol and sublimed. The sublimed product is in longflat needles and is blue and has the composition C32H16NaBe.

In a moist atmosphere it absorbs water and gives a blue powder, which isthe dihydrate. The sublimation referred to above may be replaced bycrystallising from boiling quinoline or pyridine, except that the bluercompound then obtained contains solvent of crystallisation.

The metal-free compound is obtained by dissolving the sublimed materialin concentrated sulphuric acid, pouring the solution into water,filtering off the precipitate, washing and drying.

Example 12 16.26 parts of 4-chlorophthalonitrile are ground andintimately mixed with 3.4 parts of anhydrous zinc chloride. The mixtureis heated with stirring at 230-240 C. for 2 hours. The resulting mass iscooled, ground, extracted with boiling alcohol and dried.

It will be understood that the details of procedure given above, forinstance as to solvent employed, temperature and duration of thereaction, method of extraction and purification, etc., may beinterchanged between the various examples, and may be varied furtherwithin wide limits, without departing from the spirit of this invention.

We claim:

1. The process of producing coloring matters of the phthalocyanineseries, which comprises heating an o-arylene-dicyanide at a temperaturebetween and 400 C. in the presence of a metalliferous reactant the metalof which belongs in the second group of the periodic table of elements.

2. The process of producing coloring matters of the phthalocyanineseries, which comprises heating an o-arylene-dicyanide at a temperaturebetween 150 and 400 C. in a solvent boiling above 150 C., in thepresence of a metal compound capable of yielding an element of thesecond group of the periodic table.

3. The process of producing coloring matters of the phthalocyanineseries, which comprises heating phthalonitrile and an oxide of a metalof the second group of the periodic system, at about the boiling pointof the reaction'mass.

4. The process of producing coloring matters of the phthalocyanineseries, which comprises heating phthalonitrile and zinc chloride in theratio of from 1 to 2 moles of the latter for each 4 moles of the former,at about the boiling point of the reaction mass, and recovering thesolid pigment thus produced. a

5. The process of producing coloring matters of the phthalocyanineseries, which comprises heating phthalonitrile with magnesium oxide in amedium of quinoline, at a temperature of about 220 to about 230 C., andrecovering the solid reaction product.

6. The process of producing coloringmatters of the phthalocyanineseries, which comprises heating phthalonitrile and metallic calcium inamyl alcohol at about the reflux temperature of ISIDOR MORRISI-IEILBRON. FRANCIS IRVING. REGINALD PATRICK LINSTEAD.

